Sex and HIV education programs have multiple goals: to decrease unintended pregnancy, to decrease STDs including HIV and to improve sexual health among youth. In 2005, almost two-thirds (63%) of all high school seniors in the US had engaged in sex, yet only 21% of all female students used birth control pills before their last sex and only 70% of males used a condom during their last sexual intercourse. In 2000, 8.4% of 15-19 year old girls became pregnant, producing one of the highest teen pregnancy rates in the western industrial world. Persons aged 15-24 had 9.1 million new cases of STDs in 2000 and made up almost half of all new STD cases in the US. There are numerous factors affecting adolescent sexual behavior and use of protection. Some of these factors have little to do with sex, such as growing up in disadvantaged communities, having little attachment to parents or failing at school. Other factors are sexual in nature, such as beliefs, values, perceptions of peer norms, attitudes and skills involving sexual behavior and using condoms or contraception. It is these sexual factors that sex/HIV education programs can potentially affect, thereby impacting behavior. Sex/HIV education programs alone cannot totally reduce sexual risk-taking, but they can be an effective part of a more comprehensive initiative.